Comparative study of synchrophasor estimation algorithms under dynamic conditions for on-line transmission line parameter estimation

This paper compares the performance of two algorithms which have been proposed in the literature to estimate the synchrophasor under dynamic conditions. Both algorithms are implemented for the estimation of transmission line parameters. The first method is an adaptive mimic phasor estimator (AMPE) based on conventional sliding DFT technique to remove the decaying dc component in the signal and obtains the accurate magnitude and angle of the signal. The second method is least error square (LES) approach which calculates phasor from digitized samples of signal where each input is assumed to be composed of a decaying dc component and components of the fundamental and harmonic frequencies. Both the algorithms are also compared with the conventional DFT. Testing of the algorithms is performed in MATLAB/SIMULINK. The results obtained shows that conventional DFT method fails to estimate phasors accurately under dynamic conditions while other two algorithms work satisfactorily. However, AMPE performance is better than LES for line parameter estimation.